In a settlement with UnitedHealth Group, New York Attorney General Andrew M. Cuomo has ordered an overhaul of the databases the industry uses to determine how much of a medical bill is paid when a patient uses an out-of-network doctor. A statement from Cuomo's office said the industry had engaged in "a scheme to defraud consumers" by systematically underpaying the nation's patients by hundreds of millions of dollars over the last decade. The move is part of a settlement with UnitedHealth Group, which operates the industry databases. It results from a yearlong investigation by Cuomo's office that concluded the data had understated the true market rates of medical care by up to 28%.